Anti-theft devices for motor vehicles comprise several different types. These include alarms or other electronic devices which disable the vehicle unless bypassed by an authorized operator with a special key or electronic code, but those devices suffer from the disadvantages of being expensive and prone to malfunction. Furthermore, alarms and electronic anti-theft devices are commonly arranged beneath the hood of the vehicle where a knowledgeable criminal may easily locate and disconnect them.
Another type of anti-theft device is one which re-strains relative movement between the operating controls at the interior of the vehicle in order to prevent the vehicle from being driven. This type of device comprises a pair of hooks at opposite ends of an elongated locking apparatus which is adjustable in length. One hook is engaged on a foot pedal and the other is positioned around the steering wheel rim. The elongated apparatus is then contracted in length and locked into position to provide a rigid and tight connection between the foot pedal and the steering wheel whereby neither of those vehicle control components can be moved relative to the other. Such connecting type anti-theft devices suffer from the serious disadvantage of being inconvenient and difficult for most consumers and motorists to use. Installation cannot be easily accomplished while sitting behind the wheel, as one must reach down to the foot pedals to manipulate the lower hook into position, and must first extend the other hook upwardly beyond the steering wheel in the direction where one would ordinarily be seated before that book can be contracted back downwardly into engagement with the steering wheel rim. These manipulations of the anti-theft device would best been carried out from the exterior of the vehicle with the door open, but that approach suffers from obvious disadvantages in terms of adverse weather conditions, available space and parking locations, and simple preference for convenience. Furthermore, the lock on a device of that type is located inconveniently out of reach beneath the steering wheel.
A third and more successful type of vehicle anti-theft device is one which is mounted solely on the steering wheel to prevent the wheel from being turned. This type of anti-theft device usually comprises a metal bar mounted diametrically across the steering wheel and having an elongated projection at one end extending substantially beyond the rim of the steering wheel to come in contact with the vehicle interior and thereby to prevent complete rotation of the steering wheel when the wheel is turned. The steering wheel lock type of anti-theft devices are installed and operate independently of other interior vehicle control components, and thus overcome the disadvantages associated with the aforementioned connecting type of anti-theft device. However, known steering wheel locks do suffer from several disadvantages associated with mounting of the metal bar across the steering wheel rim. For example, U.S. Pat. 4,103,524 to Mitchell et al shows a pair of hooks for mounting the elongated bar on the steering wheel rim, but is limited in its application to rims having a diameter corresponding to the fixed hook spacing. This problem is overcome by the steering wheel lock shown in U.S. Pat. No. 4,304,110 to Fain, wherein the mounting hooks are provided on separate rod members with the spacing therebetween being adjustable by means of a threaded connection between the separate rod members. This is an improvement over the arrangement in the Mitchell patent, but is not entirely convenient and easy to use as it would be somewhat time consuming to make the required adjustments. It is known to provide the steering wheel rim books on separate elongated members which are telescopically axially shiftable with respect to each other and which may be locked at a number of spaced axial positions, as shown in British Patent Application GB 2039840A. However, that device requires the two telescopic members manually be held in position to align apertures extending therethrough such that a pad lock shaft can be inserted through the apertures to lock those members in the desired axial position. The user must inconveniently manipulate the pad lock with one hand while holding the telescopic members with the other.
The adjustment and handling problems associated with the aforementioned steering wheel locks are substantially overcome by the device shown in U.S. Pat. No. 4,738,127 to Johnson, assigned to the present assignee. One rim hook of that steering wheel lock is provided on an elongated tubular member, and the other rim hook is provided on an elongated rod member telescopically receivable in the tubular member. The rod member has a series of circumferentially extending grooves closely spaced along its length. A lock housing is provided where the rod member is received in the tubular member and includes a spring biased retainer at a fixed axial position. The retainer is spring biased into engagement with the particular rod groove at that axial location to loosely hold the rod member steady in the tubular member. The housing also includes a key lock cylinder which turns a torque blade into engagement with the retained rod groove to securely lock the rod in that axial position. The closely spaced rod grooves advantageously define a great number of positions at which the rim hooks may be spaced apart, and the retainer advantageously holds the spaced hooks at the desired position to free the user's hands for attention to the key and lock.
The prior patented steering wheel lock of the present assignee successfully overcomes the disadvantages in adjustment and handling discussed above with respect to the previously known steering wheel locks, but still is not ideally convenient and easy to use. Although the retainer conveniently holds the hooks in the desired spaced location on the steering wheel rim, the user must use a key to lock the telescopic members in that position. Use of the key is again required when the steering wheel lock is to be removed. Each use of the steering wheel lock between operations of the motor vehicle thus requires two operations with the key lock. Since speed and convenience are strict requirements of most motorists, and since one usually operates an automobile several times daily, these repeated operations with a key in addition to those normally required to enter and operate an automobile could be prohibitively cumbersome whereby a motorist may frequently neglect to use the steering wheel lock and may ultimately abandon it.
A steering wheel lock shown in U.S. Pat. No. 3,462,982 to Moore has one wheel rim hook carried on a lock member which is slidable along a ratchet bar. The lock member is slidable on the ratchet bar only in a radially outward direction unless an associated key lock is unlocked. The ratchet mechanism obviates the need for a manual key operation to secure the slidable rim hook in its radially outward position mounted on the steering wheel rim. Reduction in the frequency of key use is a relative advantage of the steering wheel lock shown by Moore, but that device suffers from several other disadvantages which render it highly impractical as an anti-theft device to be used on a daily basis by typical consumers and motorists. Exposure of the ratchet bar and connecting elements between the ratchet bar and the body of the steering wheel lock present numerous sharp edges and pinch points where a user's fingers could easily become injured during manipulation of the device. The same structural features present pry points in which a criminal could easily inset and wield a crowbar to destroy and remove the device. Even if the exposed parts could withstand application of a crowbar, they present the appearance of being susceptible to forcible removal. The appearance of the device would not discourage a potential thief and could not prevent the damage associated with unauthorized entry into the vehicle preliminary to the attempt to remove the steering wheel lock. An additional disadvantage of a steering wheel lock of the type shown by Moore is that the elongated body member, as well as the exposed ratchet bar, are formed of flat bar stock. The rectangular cross-section of these members does not allow for relative rotation of the rim hooks about the axis of the elongated body member. In use, the preferred orientation of an installed steering wheel lock would be horizontally across the front of the steering wheel, and rotation of the hooks relative to one another may often be desirable to mount the hooks around wheel spokes which may join the rim at the horizontally opposed locations.
The prior art is thus seen to fail to provide a steering wheel lock which is easily and conveniently mounted on a steering wheel with a minimum of manual manipulation and which securely and effectively discourages theft of the vehicle.